Fiber device with high nonlinearity, dispersion control and gain

Abstract

An optical fiber is tapered, for example, by heating it with a CO2 laser. The tapering process is controlled such that the taper transition regions have taper angles selected to minimize loss. The taper waist has a diameter selected to introduce desired dispersion properties and desired nonlinearity. The optical fiber can be used as a dispersion compensator in a fiber laser or other fiber optic system. The nonlinearity in the tapered optical fiber allows the generation of ultrashort light pulses.

Description

REFERENCE TO RELATED APPLICATION[0001]The present application claims the benefit of U.S. Provisional Patent Application No. 60 / 516,299, filed Nov. 3, 2003, whose disclosure is hereby incorporated by reference in its entirety into the present disclosure.FIELD OF THE INVENTION[0002]The present invention is directed to an optical device having an optical fiber and more particularly to such a device in which the fiber is heated and drawn to control at least one of loss, gain, dispersion and nonlinearity. The invention is further directed to a method of making such a fiber.DESCRIPTION OF RELATED ART[0003]It is well known that optical fibers can be heated and drawn down to sizes much smaller than a typical single-mode fiber. Heating techniques using an electric arc, flame, and CO2 laser absorption have all been shown.[0004]A system for carrying out the CO2 laser absorption technique is shown in FIG. 1. As shown in FIG. 1, light L1 from a CO2 laser 102 at up to 25 W power and light L2 from...

AI Technical Summary

Benefits of technology

The present invention relates to a technique for tapering optical fibers to achieve desired properties such as loss, gain, dispersion, nonlinearity, and more. The invention aims to minimize the formation of transition regions and external dispersion-correcting elements, and to use tapered fibers for dispersion compensation in fiber lasers and optical amplifiers. The tapered fibers can also be used in optical devices such as optical logic devices and lossless stand-alone dispersion compensators. The invention provides a solution to the need for external optics in conventional fiber lasers, making them more compact and inexpensive. The tapered fibers can also be used for ultra short optical pulses and in optical amplifiers. The invention has been experimentally verified and can be used in various applications such as modelocked fiber lasers, dispersion compensation, and optical logic devices.

Problems solved by technology

Also, in the long-wavelength band (near 1550 nm) where telecommunication is normally carried out, dispersion is anomalous, leading to soliton formation.

In a conventional doped optical fiber laser, complex external optical elements are needed to compensate for the normal dispersion of the fiber, thus increasing the size, expense, and complexity of the system.

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